Hydraulic-power plant.



H. SPILLMANN.

HYDRAULIC POWER PLANT.

' APPLICATION FILED FEB. 19, 1912. 1,064,390. Patented June 10, 1 913.

7 SHEETS-SHEET 1.

H. SPILLMANN.

HYDRAULIC POWER 'PLANT.

7 APPLICATION IILIED FEB. 19, 1912.

7 SHEETS-SHEET 3.

Patented June 10, 1913.

H. SPILLMANN.

HYDRAULIC POWER PLANT. APPLICATION FILED FEB. 19, 1912.

Patented June 10,1913.

7 SHEEN-SHEET 4.

5 RI EEQ O E Q @(Q i a I H. SPILLMANN.

HYDRAULIC POWER PLANT.

APPLICATION FILED FEB. 19,-1912.

Patentd June 10, 1913.

7 SEBETQ-BHEBT 6.

H. SPILLMANN.

HYDRAULIC POWER PLANT.

APPLICATION FILED PEBIQ, 1912.

Patented June 10,1913.

H. SPILLMANN.

HYDRAULIC POWER PLANT. APPLICATION FILED 213.19, 1912.

Patented June 10, 1 7

HEINRICH SPILLMANN, OF ZURICH, SWITZERLAND.

HYDRAULIC-POWER PLANT.

Specification of Letters Patent. Patented J 1119 10, 1913,

I Application filed February 19, 1912. Serial No. 678,685.

To all whom it may concern:

Be it known that I, HEINRICH SPILLMANN, a citizen of the-Swiss Republic, and residing at Zurich, Switzerland, have invented certain new and useful Improvements in Hy draulic-Power Plants, of which thefollowing is a specification.

The subject-matter of my invention is a hydraulic power plant whose essential feature is that the double-acting pump-plunger and press-plunger of the hydraulic power plant. operate in such manner in a system completely shut off from the action of the outer atmosphere and completely filled with liquid that, without any change in the magnitude of thetetal volumetric capacity of the system filled with liquid, to each increase in volume of the chambers connected to the delivery chamber of the'double-acting pump there nevertheless corresponds an equally large diminution in volume of the chambers connected to the suction chamber of the double-acting pump and, reversely, to each diminution in volume of the former chambers there corresponds an equally large increase in volume of the latter chambers.

Hydraulic machines of all kinds can be provided with a hydraulic power plant according to my invention. Hydraulic machines for pressing, embossing, riveting, stamping, perforating or hydraulic shears, as well as hydraulic lifting gear can be operated in the described manner, and it is immaterialwhether these machines are portable or stationary. More particularly, a hydraulic power plant according to the invention can be used for tilting Bessemer converters and for turning the rudders of ships, because particularly in the latter case,

which is specially suitable for the employment of the invention, motive power due to high speed and small force must be converted into work of great force at low speed.

In the abovedescribed hydraulic plantmany advantages are obtained as compared with well-known hydraulic machines; for example, owing to the atmosphere exercising no action on the working liquid of the hydraulic machine the entire liquid of the machine constitutes, as it were, one uniform rigid body, and a" perfectly positive circulation of liquid occurs both in the delivery, and in the suction chamber of the system and in the chambers connected thereto. Thus, when the pumpplungers move, al-

though no suction or delivery air-vessel is employed, the column of liquid in the machine can never rupture, so that no hydraulic hammering and blows with their injurious consequences for the pump and gearing can ever occur; Further, a hydraulic machine according to my invention is able to work in any desired position without the system filled with liquid emptying, and without the machine being subjected to any injurious strain. Furthermore, the herein described hydraulic plant may comprise a high-speed, higlrpressure pump which possesses no kind of suction and delivery airvessel, as Well as valves Without any auxiliary load, because the acceleration and retardation of the column of liquid take place positively both in the suction chamber and also inthe delivery chamber and in the chambers connected thereto whenever the plunger of the pump moves.

In a hydraulic machine constructed according to my invention it is necessary. that the pressplunger of the machine be rigidly 0on nected with a second plunger or piston of equal volumetric displacement which works in a chamber connected to the suction chamber of the pump while the press-plunger moves in a chamber connected to the delivery chamber. This balancing plunger or piston is preferably formedwith a large and a small piston, whereby I attain that the return movement of the press-plunger takes place at a velocity considerably greater than that ofthe forward movement thereof.

Another important feature of my invention is that owing to suitably arranged valves, or to the arran ement of the driven pistons of the press-cylinder and of the ports in the manner ofa slide-valve, provision is made that when the press-plunger is in its end position the suction and delivery chainbers of the system are automatically connected, because otherwise the )arts of the gearing in the machine could c subjected to undesirablevstrain.

A hydraulic power plant according to my invention also comprises a device which revents an evacuated space being formed w ion a diminution of liquid occurs, say in consequence of leaks, within the system shut off from the atmosphere. This device substantially consists of a loaded, displaceable piston or the like which bounds the system ;iilledwith liquid, and moves forward when a diminution of liquid occurs and thereby diminishes the volumetric capacity of the system.

When the hydraulic power plant constructed according to my invention constitutes a hydraulic machine of the type of a hydraulic press, 6. g. a riveting-machlne, this machine can be very conveniently combined with a late-closer which, before a rivet i's presse compresses the plates to be riveted. The plate-closer is constructed like the main press, it being carried by press-plungers which are likewise connected with balancing pistons ;.by means of a separate pipe from the distributing device these pistons are operated in such manner through the medium of the operating lever that the plate-closer die is first pressed down, then the press-plunger provided with the snap head die is driven forward while the plate-closer die remains under pressure, and lastly the closing die is subsequently lifted. The closing die drives with it the press-plunger until, when reaching its end position, the balancing pistons of the platecloser automatically. connect the delivery chamber of the machine with the suction chamber.

For the purpose of making it impossible for a machine provided with a plate-closer to be operated improperly, such a machine is provided with a hydraulic locking device for the operating lever whose locking member, located in its rest position in the path of the operating lever, is connected with a spring-pressed piston; the piston 1s in the system led with liquid and, under the action of the liquid pressure, removes the locking member out of the way of the operating lever only when the plate-closer die is pressed down, so-that the operating lever can be moved still farther for the purpose of startin the motion of the pressplunger only a er the closing die has been pressed down. i A

One illustrative embodiment of my invention is represented by way of example in the accompanying drawing, wherein Figures 1 and 2 are side elevation and front elevation, respectively, showing a* complete hydraulic riveting-machine according to the invention, but without the platecloser; Figs. 3 and 4- are'diagrams showing the internal connection of this machine, Fig. 3 showing the parts of the machine at the moment after the termination of the depression of the press-plunger, the controlling members being still adjusted to pressure, while Fig. 4 shows the parts of'the machine at the moment after the press-plunger has been lifted, that is while the machine runs idle. Figs. 5 and 6 are side and front elevation, respectively, showing part of a machine comprising a plate-closer, and Figs.

44. Owing to employing the 7, 7, 8 and 9 are diagrams showing the internal connections of the latter machine and its plate-closer; Fig. 7 shows the machine in its rest position with the pressplunger raised, Fig. 8 in the position in which the plate-closer commences to operate and Fig. 9 in the compressing position, While Fig. 7 is a detail View.

Referring to the drawings, the hydraulic riveting machine represented in Figs. 1 to4 substantially consists of the high-pressure double-acting piston-pump a driven by an electric motor 1, the part 1 of the press, the distributing device 0, and the speed governor d not shown in Figs. 1 and 2. The

machine is arranged in such manner that it can be readily conveyed from place to place and comprises a suspension how 44 to whose two ends is. attached in a novel and improved manner a flexible suspension member 45, e. g. a chain, rope, belt or the like. The machine is suspended by means of this member 45 from a sprocket-wheel 45 which can be rotated by means of a-hand-wheel 46 so that the entire machine can be readily rotated in a plane passing throu h the bow exible sus pension member the how 44 may remain un Worked, e. can be employed in its un- .-trimmed cast condition. When the machine is to be employed vertically I use a special base-plate 65 which is a member independent of the machine proper, and consequently the weight of the machine is less during transport and when used suspended than ifthe base-platewere rigidly attached to it.

The machine represented in Figs. 5 to 9 comprises the plate-closer g and the hydraulic locking device it in addition to the other parts of the machine.

I' will now describe the construction of the machine shown in Figs. 1-4 with reference to its mode of operation. Themotor 1 imparts its rotatory motion in known manner to a crank-shaft 66 by which it is imparted by a connecting-rod 39 toan adjustable lever 2. The piston 3 of a double-acting, high-speed, high-pressure force pump possessing neither suction nor delivery airvessel is connected with this lever. When theplunger 3 moves liquid is sucked out of the suction ipe 4 and liquid is forced into the pipe 9, 0th the suction valve 5 and the .pressure valve 6, and the suction valve 7 and the pressure valve 8 opening alternately. Each movement of the plunger 3 results in a diminution in volume of equal size in both the suction chamber and also in the delivery chamber which is of importance for the running of the machine. After flowing through the pressure valves 6 and 8 the liquid passes into the pi es 9 and 2S and arrives between the two istributing pistons 11 and 12 of the distributing device 0.

with the operating leverlO' shown in Fig. 3, e. in the pressure position, the liquid under pressure is conducted through the pipe 13 to over the'press-plunger 14 movable in the pressure chamber 15' in the presscylinder 15. The press-plunger consequently moves downward, because the valve 16 in the press-cylinder is normally closed, as shown in Fig. 4, and finally arrives into its lowest position shown in Fig. 3. When the plunger 14 moves downward itdrives the balancing piston 18, 19 comprising the two pistons 18 and 19, which is movable in the balancing chamber 15 and is connected by the rod 17 with the plunger 14. The liquid under the piston 18 escapes through the. pipe 20 into the distributing box or cylinder 10 and hence into the pipe 23. The liquid under the piston 19 escapes through the pipe 22 also into the pipe 23. As'the total area of the pistons 18 and 19 is equal to the operative area of the plunger 14, the volume of liquid displaced by the piston 18, 19 is equal to the volume of liquid which enters over the plunger. The pipe 23 conducts the liquid through the cylinder 10, the duct 24, the box 26 of the pressure adjusting valve 67, and from here through the pipe 25 and the casing 27 of the hydraulic speed governor (1 into the abovementioned suction pipe 4. As soon as the piston 19 has reached its lowest position it abuts against the top end of the rod 16 of the valve 16 and opens this valve so that a sure of the machine tool.

connection of the plunger chamber 15 is established with the pipe 22 and a .circu-lation of liquid not under pressure occurs.-

The maximum height of the hydraulic pressure produced in the pipe 28 and conse-, quently above the plunger 14 is limited by the valve 67 which is pressed by means of an adjustable weight 32 or a spring on its seat. The load on this valve is'so adjusted that it corresponds to the desired working pres I If this pressure f is exceeded the valve (37 controlling the: branch pipe 29 to the pipe 28 opens until the l hydraulic pressure hasadiminished to the maximum admissible value. The valve 67 has a guide-rod 31 having a section equal to that of the valve-rod 30, so that when the position of the valve changes no change of volume of the chamber in the box 26 takes place. The liquid pressure. existing in the pipes 9 and 28 when the distributing valvegear is in the position shown in Fig. 3 is used for regulating the velocity of the pressplunger by operating in the governor d. This governor comprises a casing 27 in which is slidable a piston 33 which is under the influence of both a spring 34 and the liquid pressure in the pipes 9 and .28. Ac cording to the height of the liquid pressure for the time being the -piston 33 occupies various posit-ions in itscasing 27. The lower end of the piston-rod 33 is connected with one arm 35 of a two-armed lever 35, 37 fulcrumed at 36 on the frame of the machine. The other arm 37 of this two-armed lever isconnected in such manner with the lever 2 that a change of position of the arm 37 causes 'a change of position of the lever 2 and its point of attachment 38 to the connecting-rod 39. vOwing to the change of position of the lever 2 the stroke of the pump-plunger 3 is varied in such manner that. when the pressure on the piston 33 increases, the stroke of the plunger piston decreases and consequently the velocity of the press-plunger 14 is diminished. Owing to the piston-rod 33 being equally thick at the two sides of its piston 33, when this piston changes its position an equally large change of volume occcurs in the suction and delivery chambers of the machine. At the end of the suction pipe 4, thus at a place which is never subjected topressure, is arranged that device which prevents an evacuated chamber being formed should a diminution of liquid occur inside the system, say in consequence of leaks. For receiving this device the top end of the body 40 of the pump is formed like a casin and contains aspring-pressed piston 41. dNhen the circulation of the liquid is normal this piston does not. move, because the volumes of liquid in the suction chamber and in the delivery chamber displaced by the movable members of the machine in the system are equally large. If a diminution of liquid occurs in the system owing to leakage, however, whereby an' evacuated chamber disturbing the running of the machine would be formed, the piston 41 is automatically pushed forward so'that an evacuated chamber cannot form. The piston-rod 41. is preferably graduated or provided with a mark in operative relation'with a scale, so that the level of the liquid in the system is indicated by the position of this piston-rod. The piston 41 is so arranged that it can be removed together with its spring 41 out.

of the casing, so that fresh liquid can be poured through the opening thus made into the system.

In contradistinction to Fig. 3 which shows the pants of the machine at the moment after the termination of the downward motion ofithe press-plunger, 2'. c. in the pressure position, Fig. 4 shows the machine at the moment after the press-plunger has begun to be lifted, 2'. e. when running idle. \Vhen the operating lever together with the pistons 11 and 12 connected with it are moved out of the position shown in Fig.3 into that shown in Fig. 4, the liquid is led out. of the pipe 28 through the pipe 20 to under the small piston 18 of the piston 18, 19.'

This is thereby lifted and elevates the plunger 14 with .as much greater velocity as the area of the piston 18is smaller than the area of the plunger 14. The guide 64 of the piston is of such a length that as soon as the plunger 14 has reached its highest position the piston 18 leaves this guide 64, whereby the connection between the delivery and suction chambers, z. e. the connection between the pipes 20 and 22 and 13,.is again established. By designing the guide 64 in this Way I provide that the highest position of the plunger 14 is limited without the aid of a Valve which, having regard to the rapid velocity of lift, results in a very simple plant certain of operation. The plunger 14 and the pistons 18 and 19 connected together remain in their upper position when the dis tributing members 11, 12 are in the position shown in Fig. 4, because the frictional resistance of the leather-collars of the plunger and pistons and of the packing of the rod 17 is so great that it cannot be overcome by the weight of the parts 14, 17 18. The distributing pistons 11 and 12 together with their piston-rods are so constructed that their displacement does not result in a change of volume in either the suction chamber or in the delivery chamber.

The plate-closer comprised in the machine represented in Figs. 5 to 9 which compresses the plates before .pressing a rivet comprises a casing 43 in which move the two plate-closing plungers 61 having the pistonrods 62 and the balancing piston 63. Between the chambers containing the plungers 61 and the pistons 63 are arranged valves 16 having the same function'as the valve 16 I described above with reference to Figs. 8 and 4. The two plungers 61 are connected below by the plate-holder or closing die 47 which imparts the total pressure to the plate to be compressed. The additional details of the plate-closer will now be explained with reference to their mode of operation and to Figs. 7, 8 and 9. In the position of the operating lever 53 shown in Fig. 7, 2'. 6. in the idle position of the machine, the liquid supplied by the pump flows through the pipe 28 to between the pistons 11 and 12 in the distributing device and flows through the pipes 20 and 57 to under the two balancing pistons 63. As these pistons are already in their highest position a connection with the pipe 22 is established through the additional ducts 60. The space underthe pistons 18, 19 is permanently connected with the pipe 22, and the liquid consequently returns through the pipe 23, duct 24, and pipe 25 to the pump without any pressure being produced. Thus when the operating lever is in the position shown in Fig. 7 the liquid circulates without exerting any appreciable pressure. operating lever 53 is-tilted over out of its position shown in Fig. 7 into that shown in Fig. 8, in which the plate-closer operates,

Now when the J the distributing pistons 11 and 12 occupy a difierent position relatively to the ap pertaining pipes. The pressure liquid then flows from the pipe 28 through the ports 59 in the middle distributing piston 58 (Fig. 7) provided in addition in a machine having a platecloser, and through the pipes 54, I 55, and 56 to over the two plate-closer These then move downward' 4 of the pump. When the closing die 47 is stopped by striking on the plates to be compressed, the liquid above the plungers 61 and in the pipes 28, 54,55 and 56 is subjected to pressure. As soon as the liquid in the pipes 54 and 55 is subjected to pressure the safety device it connected with the plate-closer for preventing improper operation is actuated. This safety device It comprises the casing 48 containing a piston 49 which is pressed by a spring 51, and has a piston-rod 50. The spring 51 presses the piston 49 so low down in the position of the parts of the machine shown in Figs. 7

and 8 that the piston-rod 50 projects into the path of the catch 52 of the operating lever 53. In this position of the pistonrod 50 the operating lever 53 can'not'be moved out of the position shown in Fig. 7 by way of the position shown in Fig. 8 intothe position shown in Fig. 9 which would cause disturbance in working. As soon as pressure occurs in the pipes 54 and 55 which open below the piston 49' of the hydraulic safety device, however, the piston 49 together with p the piston-rod 50 is lifted and the catch 52 is released, so that it can now be returned into the position shown in Fig. 9 in whichthe rivet is closed In thisposition of the operating lever according to Fig. 9, the pressure liquid delivered by the pump flows through the pipe 28 to between the dis? tributing pistons 11 and 12 and through" the-pipe 13 to over the press-plunger 14 and drives the latter together with the piston 19, 18 downward. The closing die 47 remains under pressure as the pipe 54 is now closed by the piston 58. The liquid displaced when the press-plunger moves downward returns through the pipes 22, 23,and

25 to the pump. As soon as the press-plum.

ger 14 and with it the closing plunger-s61 have arrived at their lowest positions a connection is automatically established bee tween the deliveryand suction sides of the pump owing to the valves 16 opening. When the operating lever is returned out of its pressing position as shown in Fig. 9 into its rest position as shown in Fig. 7, the pressure liquid flows out of the pipe 28 through the pipes 20, 57 to under the balancing plungers 63. These plungers are lifted together with the plungers 61 and the closing die 47, the closing (lie simultaneously driving the plunger 14 and the pistons 19, 18 upward. The liquid displaced by the two plungers (it then returns through the pipes 56, 55, 54, duct 24 and pipe 25 to the pump, While the liquid displaced by the press-plunger 14 flows through the pipes 13, 23, 22, ducts 60 and ($8 to under the pistons 18 and 19. The movement of the plungers 14 and 61 ceases as soon as the plungers 63 open the ports 60, because at this moment the liquid can circu late without exerting any material pressure, as described above with reference to Fig. 7 When the plungers 14 and 61 move backward the liquid pressure also ceases in the casing 48 of the safety device it, so that the spring 51 drives the piston 49 forward into its locking position shown in Fig. 7

I claim 1. In a hydraulic power plant, the combi nation with a closed hydraulic system filled with liquid, shut oil from the influence of the atmosphere and comprising a suction chamber, a delivery chamber, and a doubleacting piston pump connected with said chambers, of a cylinder containing a pressure-chamber, and having a second chamber adapted to be connected with said suction chamber, a press-plunger movable in said pressure-chamber, a memberrigidly connected with the pressplunger and movable in said second chamber, and distributing means for connecting the said pressure chamber either with the said delivery chamber or with the said suction chamber, the volumetric displacement of the liquid caused during two or more strokes of the doubleacting piston-pump by the motion of the said member being equal to that caused by the motion of the press;plunger.

2. In a hydraulic power plant, the combination with a closed hydraulic system filled with liquid, shut off from the influence of the atmosphere and comprising a suction chamber, a delivery chamber, and a doubleacting piston pump connected with said chambers, of a cylinder containing a pressure-chamber and a balancing chamber, a press-plunger movable in said pressurechamber, a balancing piston rigidly connected with the press-plunger and movable in said balancing chamber, and distributing means for connecting the sai'd pressure chamber either with the said delivery chamber or with the said suction chamber, and the said balancing chamber either with the said suction chamber or with the said delivery chamber; the volumetric displacement of the liquid caused during two or more strokes of the double-acting piston pump by the motion of the said balancing piston being equal to that caused by the motion of the mess-plunger.

3. In a hydraulic power plant, the combination with a closed hydraulic system filled with liquid,shut oil from the influence of the atmosphere and comprising a suction chamber, a delivery chamber, and a doubleacting piston-pump connected with said chambers, of a cylinder containinga pressure-chamber and a balancing chamber, a press-plunger movable in said pressure chamber, a balancing piston rigidly connected with the press-plunger and movable in 7 said balancing chamber, distributing means for connecting the said pressure 7 chamber either with the saiddelivery chamber or with the said suction chamber, and the said balancing chamber either with the said suction chamber or with the said delivery chamber, and means in the balancing chamber coacting with the said piston for automatically connecting the delivery chamher with the suction chamber in the outer end position of the press-plunger, the volumetric displacement of the liquid caused during two or more strokes of the doubleacting piston-pump by the motion of the said balancing piston being equal to that caused by the motion of the press-plunger.

4. In a hydraulic power plant, the combination with a closed hydraulic system filled with liquid, shut oil from the influence of the atmosphere and comprising a suction chamber, a delivery chamber, and a doubleacting piston-pump connected with said chambers, of a cylinder containing a pressure-chamber and a balancing chamber, a press-plunger movable in said pressurechamber, a balancing piston comprising a larger and a smaller piston rigidly connected with the press-plunger and movable in the said balancing chamber, and a wall or guide in said balancing chamber dividing the same into a smaller and a larger chamber, the said larger piston being movable only in the said larger chamber and the said smaller piston being movable in both the smaller and larger chambers, a pipe connected to said pressure chamber, a suction pipe connected to said larger chamber, a pipe connected to said smaller chamber, and a distributing device connecting said suction pipe to said suction chamber, and adapted to connect the former and latter pipes to said delivery and suction chambers, respectively, and reversely, the volumetric displacement of the liquid caused during two or more strokes of the double-acting piston-pump by'the motion of the said balancing piston -being equal to that caused by the motion of the press-plunger.

5. In a hydraulic power plant, the combination with a closed hydraulic system filled with liquid, shut oil from the influence of the atmosphere and comprising a suction chamber, a delivery chamber, and a doubleacting pistonpump connected with said chambers, of a cylinder containing a pressure-chamber and a balancing chamber, a press-plunger movable in said pressure-- chamber, a balancing piston comprising a larger and a smaller piston rigidly connected with the press-plunger and movable in the said balancing chamber, and a wall or guide in said balancing chamber dividing the same into a smaller and a larger chamber, the said larger piston being movable.

only in the larger chamber, and the smaller piston being movable in both the smaller and larger chambers, a pipe connected to said pressure chamber, a suction pipe connected to said larger chamber, a pipe connected to said smaller chamber, and a distributing device connecting said suction pipe to said suction chamber, and adapted to connect the former and latter pipes to said delivery and suction chambers, respectively, and reversely, a connection being between the two latter pipes in said balancing chamber when the smaller piston leaves said guide, for the purpose specified.

6. In a hydraulic power plant, the combination with a closed hydraulic system filled with liquid, shut 0E from the influence of" the atmosphere and comprising a suction chamber, a delivery chamber and a double acting piston-pump connected with said chambers, of a cylinder containing a pressure-chamber and a balancing chamber, a press-plunger movable in said pressurechamber, a balancing piston rigidly connected with the press-plunger and movable in said balancing chamber, means for automatically connecting the pressure chamber with thebalancing chamber in the outer end position of the press-plunger, and distributing means for connecting the said pressure chamber either with the said delivery chamber or with the said suction chamber, and

the said balancing chamber either with the said suction chamber or with the said delivery chamber, the volumetric displacement of the liquid caused during two or more strokes of the double-acting piston-pump by the motion of the said balancing piston be-* ing equal to that caused by the motion of the press-plunger. r

7. In a hydraulic power plant, the combination with a closed hydraulic system filled with liquid. shut 0H from the influence of the atmosphere and comprising a suction chamber, a delivery chamber, and a doubleacting pistonpump connected with said chambers, of a cylinder containing a pressure-chamber and a balancing chamber, a press-plunger movable in said pressurechamber, and a balancing piston rigidly connected with the press-plunger and movable in said balancing chamber, a port conoeaseo meeting the pressure-chamber with the balancing chamber, and ,a loaded valve normally closing said port, said valve having a valve rod extending into the balancing chamber and adapted to be driven by said piston,-and distributing means for connect ing the said pressure chamber either with the said delivery chamber or with-the said suction chamber, and the said balancing chamber either with thesaid suction chamber or with the said delivery chamber, the volumetric displacement of the'liquid caused during'two or more strokes of the'double acting piston-pump by the motion of the said balancing piston being equal to that caused by the motion of the press plunger.

8. In'a hydraulic power plant, the combination with a closed hydraulic system filled with liquid, shut off from the influence of the atmosphere and comprising a suction chamber, a delivery chamber, and a doubleactingpiston-pump connected with said chambers, of a cylinder containing a pres sure-chamber and a balancing chamber, a

press-plunger movable in 'said pressurechamber, a balancing piston rigidly connectedwith the press-plunger and movable in said balancing chamber, and distributing means for connecting the said pressure chamber either with the said delivery chamber or with, the said suction chamber, and the said balancing chamber either with the said suction chamber or with the said de-' livery chamber, said suction chamber having a part formed as a cylinder, and a loaded, movable, closure piston in" said cylinder, the volumetric displacement of the liquid caused during two or more strokes of the double-acting piston-pump by the motion of the said balancing piston being equal to that caused by the motion of the press plunger.

'9. In a hydraulic power plant. the combination with a closed hydraulic system filled with liquid, shut off from the influence of the atmosphere and comprising a suction chamber, a delivery chamber and a double acting piston-pump connected with said chambers, of a casing comprising both a press-plunger chamber, a balancing pistonchamber, a closing-die-plunger chamber and a balancing plunger-chamber, a press-plunger movable in said press-plunger chamber, a balancing piston movabie in said piston-chamber and rigidly connected with the press-plunger, a closing die plunger movable in said closing-die-plunger chamber, a closing die attached to the latter plunger, a port in the casing connecting the said, pistonchamber with the said balancing plunger chamber, a balancing plunger movable in said balancing plunger-chamber normally closing saidport and rigidly connected with means for connecting the chambers in said casing to said suction and delivery chambers, the said closmg-die-plunger chamber being first connected to the said delivery chamber, the press-plunger chamber being subsequently connected to the said delivery ch amber, whereupon the press-plunger chamber is connected to the said suction chamber and the balancing plunger-chamber is connected to the said delivery chamber.

10, In a hydraulic power plant, the combination with a closed hydraulic system filled with liquid, shut oii from the influence of the atmosphere and comprising a suction chamber, a delivery chamber and a doubleacting piston-pump connected with said chambers, of a casing comprising a pressplunger chamber, a balancing piston-chamber, a closing-die-plunger chamber and a balancing plunger-chamber, a press-plunger movable in said press-plunger chamber, a balancing piston movable in said piston-chamber and rigidly connected with the press-plunger, a closing-die plunger movable in said closing-die-plunger chamber, a closing die attached to the latter plunger, a port in the casing connecting the piston chamber with the balancing plunger-chamber, and a balancing plunger movable in said balancingplunger chamber, normally closing said port and rigidly connected with said closing-die plunger, distributing means comprising a cylinder, three rigidly connected .pistons in the cylinder, the middle piston cf the said three pistons having ports in the same, and an operating lever connected to the said three pistons, and .pipes, substantially as shown, connectin the said cylinder with the said chambers or actuating said plungers therein.

11. Ina hydraulic power plant, the combination with a closed hydraulic system filled with liquid, shut off from the influence of tin atmosphere and comprising a suction chamber, a delivery chamber and a double acting piston pump connected with said chambers, of a casing comprising both a press-plunger chamber, a balancing pistonchamber, a closing-die-pllinger chamber and a balancing plunger chamber, a press-plunger movable in said press-plunger chamber, a balancing piston movable in said piston-chamber and rigidly connected with the press-plunger, a closing-die plunger movable in said closing-die-plunger chamber, a closing die attached to the latter plunger, a port in the casing connecting the said pistonchamber with the said balancing plunger chamber, a balancing plunger movable in said balancing plunger-chamber, normally closing said port and rigidly connected with said closing-die plunger, a distributing device connected to said suction and delivery chambers, said distributing device comprising a cylinder, and three rigidly connected pistons of equal size in the cylinder, the

middle piston of the said three pistons hav- HEIN RICH SPILLMA-N N \Vitnesses:

CARL GUBLER, HARRY A. MoBmnE. 

